--- a/mercurial/upgrade.py Tue Jun 05 08:19:35 2018 +0200
+++ b/mercurial/upgrade.py Mon Jul 16 17:10:52 2018 -0700
@@ -259,6 +259,28 @@
'faster')
@registerformatvariant
+class sparserevlog(requirementformatvariant):
+ name = 'sparserevlog'
+
+ _requirement = localrepo.SPARSEREVLOG_REQUIREMENT
+
+ default = False
+
+ description = _('in order to limit disk reading and memory usage on older '
+ 'version, the span of a delta chain from its root to its '
+ 'end is limited, whatever the relevant data in this span. '
+ 'This can severly limit Mercurial ability to build good '
+ 'chain of delta resulting is much more storage space being '
+ 'taken and limit reusability of on disk delta during '
+ 'exchange.'
+ )
+
+ upgrademessage = _('Revlog supports delta chain with more unused data '
+ 'between payload. These gaps will be skipped at read '
+ 'time. This allows for better delta chains, making a '
+ 'better compression and faster exchange with server.')
+
+@registerformatvariant
class removecldeltachain(formatvariant):
name = 'plain-cl-delta'